Florida prosecutors expected to request that would-be Trump assassin Ryan Routh remain detained at US court hearing on Monday.

The man accused in the apparent assassination attempt of former US President Donald Trump at a golf course in Florida left behind a note saying that he intended to kill the political candidate and kept in his car a handwritten list of dates and venues where Trump was to appear, the Justice Department has said.

The new allegations were included in a detention memo filed ahead of a hearing on Monday at which the Justice Department was expected to argue that 58-year-old Ryan Routh should remain locked up as the case moves forward.

The details are meant to buttress prosecutors’ assertions that Routh is a threat to public safety and has a premeditated plan to kill Trump, a plot officials say was thwarted a week ago by a Secret Service agent who spotted a rifle poking out of shrubbery on the West Palm Beach golf course where Trump was playing.

The note was placed in a box dropped off months earlier at the home of an unidentified person who did not open it until after Routh’s arrest on September 15. The box also contained ammunition, a metal pipe, building materials, tools, phones and various letters.

One note, addressed “Dear World”, appears to have been premised on the idea that the assassination attempt would be unsuccessful.

“This was an assassination attempt on Donald Trump but I failed you. I tried my best and gave it all the gumption I could muster. It is up to you now to finish the job; and I will offer $150,000 to whomever can complete the job,” the note said, according to prosecutors.

An attorney for Routh did not immediately respond to an email seeking comment Monday morning.

Travel records

Phone records cited by the Justice Department indicate Routh travelled to West Palm Beach, Florida from Greensboro, North Carolina in mid-August, and that he was near Trump’s golf club and the former president’s Mar-a-Lago residence “on multiple days and times” between August 18 and the day of the apparent attempted assassination.

He was arrested after a Secret Service agent who was scoping the Trump International Golf Club for potential security threats saw a partially obscured man’s face, and the barrel of a semiautomatic rifle, aimed directly at him. The agent fired at Routh, who sped away before being stopped by officials in a neighbouring county.

The Secret Service has said Routh did not fire any shots and never had Trump in his line of sight.

The Justice Department also said on Monday that authorities who searched his car found six phones, including one that showed a Google search of how to travel from Palm Beach County to Mexico.

They also found a list with dates in August, September and October and venues where Trump had appeared or was scheduled to, according to prosecutors. A notebook found in Routh’s car was filled with criticism of the Russian and Chinese governments and notes about how to join the war on behalf of Ukraine.

The detention memo also cites a book authored by Routh last year in which he lambasted Trump’s approach to foreign policy, including in Ukraine. In the book, he wrote that Iran was “free to assassinate Trump” for having left an international nuclear deal.

Routh is charged with illegally possessing his gun in spite of multiple felony convictions, including two charges of possessing stolen goods in 2002 in North Carolina, and with possessing a firearm with an obliterated serial number. More serious charges are possible in the weeks ahead.